In computers, tape backup is the ability to periodically copy the contents of all or a designated amount of data from its usual storage device to a tape cartridge device so that, in the event of a hard disk crash or comparable failure, the data will not be lost. Tape backup can be done manually or, with appropriate software, be programmed to happen automatically.

Tape backup systems exist for needs ranging from backing up the hard disk on a personal computer to backing up large amounts of storage for archiving and disaster recovery purposes in a large enterprise as part of a storage area network (SAN), usually combining a hardware and software package. For personal computer tape backup, the Onstream USB tape drive is popular. For enterprise tape backup, Linear Tape-Open (LTO) is an industry open standard from Hewlett-Packard, IBM, and Seagate.

Tape backup also includes the ability to restore data that has been backed up back to hard disk storage devices when needed.

reff............http://searchstorage.techtarget.com/definition/tape-backup